1. Field of the Invention
The present invention relates to a lens-fitted photo film unit. More particularly, the present invention relates to an improvement of a lens-fitted photo film unit suitable to be produced by automated mass production.
2. Description of the Prior Art
There is disclosed a lens-fitted photo film unit as a single-use camera suggested in commonly assigned co-pending patent application U.S. Ser. No. 08/203,556. It has a film containing section, of which the rear is pre-loaded with 135 film with a cassette in a factory. The 135 film is defined by International Organization for Standardization (ISO) 1007, 1979 version. An exposure unit includes a support member, on which a taking lens, a one-frame advance mechanism and a shutter device are mounted. The rear of the film containing section is covered with a rear cover in light-tight fashion. The front of the film containing section is covered with a front cover.
After effecting all exposures on the film as loaded, the lens-fitted photo film unit is given to a photofinisher and forwarded to a photo laboratory, where an operator removes the film in its cassette from the lens-fitted photo film unit, and subjects the film to development and printing in the widely available system of photofinishing. The photofinisher returns the developed film to the customer, and provides him with photo prints as produced.
There are various types of commercially available lens-fitted photo film units: a standard type, a panoramic type which effects exposures in a horizontally long format, a wide-angle type, and a telephoto type. There is also a type changeable between standard photography and panoramic photography for exposures on a single film, as suggested in commonly assigned co-pending patent application U.S. Ser. No. 08/169,203.
The lens-fitted photo film units of the different types are structurally similar regarding the film winding mechanism and the shutter device, but different in the photographic light path, which is defined from the taking lens to the exposure plane at the film. The telephoto type of lens-fitted photo film unit has a photographic light path that is approximately twice as long as that of a standard type, as the light path of the telephoto type is Z-shaped by reflection from an arrangement of mirrors. The type changeable between standard photography and panoramic photography incorporates two opaque movable plates about the light path for shielding light. There is no compatibility of parts inclusive of the film containing section, front cover and rear cover, which are specifically designed for each of the different types.
The lack of compatibility is disadvantageous in view of the cost of manufacturing the products which are of different types but include very similar parts. The total number of the parts is greater than it need be, so that the parts are more costly than they need be. In consideration of the low prices at which the lens-fitted photo film units are sold, this incompatibility results in a greater expense of manufacture.
The support member constituting the conventional exposure unit generally has an L-shape which includes a top portion for mounting a shutter drive mechanism and the one-frame advance mechanism and a front portion for mounting the shutter blade. The L-shape has the drawback of low rigidity. If the lens-fitted photo film unit is left to stand in an environment of high temperature for a long time, e.g. the inside of a car parked outside in the midsummer, then the support member or its bosses are deformed in irrecoverable fashion. The counter wheel is affected and fails to indicate a correct number that should be indicated. Although there is a system of recycling any usable parts of lens-fitted photo film units, the exposure unit after such deformation cannot be reused even after withdrawal of the parts. The suitability of the exposure unit for reuse and efficiency of manufacture are lowered.